Magnetic anisotropy and magneto-optical effects of (Pt/Co/Pt/Ni) multilayers

DC magnetron sputter deposited (Pt/Co/Pt/Ni) multilayers which exhibited Curie temperatures in the range of 150-300/spl deg/C were studied as possible alternative multilayers for magneto-optical recording to the widely studied Co/Pt, whose Curie temperatures are in the range of 200-400/spl deg/C. These multilayers exhibited comparable magnetic and magneto-optical properties to Co/Pt multilayers with enhancement of the Kerr rotation at lower wavelengths and negligible Kerr ellipticity over a wide range of the spectrum. The dependence of the magnetic anisotropy on the thicknesses of nickel, cobalt, and platinum sublayers was studied. The surface anisotropies of nickel and cobalt were estimated as -0.003 ergs/cm/sup 2/ and 0.027 ergs/cm/sup 2/ respectively and the total volume anisotropy due to Co and Ni is estimated as -1.74/spl times/10/sup 6/ ergs/cm/sup 3/.